diff options
Diffstat (limited to 'drivers/usb/host/xhci.c')
| -rw-r--r-- | drivers/usb/host/xhci.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 6e7dc6f93978..3f912705dcef 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -175,6 +175,16 @@ int xhci_reset(struct xhci_hcd *xhci) command |= CMD_RESET; writel(command, &xhci->op_regs->command); + /* Existing Intel xHCI controllers require a delay of 1 mS, + * after setting the CMD_RESET bit, and before accessing any + * HC registers. This allows the HC to complete the + * reset operation and be ready for HC register access. + * Without this delay, the subsequent HC register access, + * may result in a system hang very rarely. + */ + if (xhci->quirks & XHCI_INTEL_HOST) + udelay(1000); + ret = xhci_handshake(&xhci->op_regs->command, CMD_RESET, 0, 10 * 1000 * 1000); if (ret) @@ -4768,8 +4778,16 @@ int xhci_update_hub_device(struct usb_hcd *hcd, struct usb_device *hdev, ctrl_ctx->add_flags |= cpu_to_le32(SLOT_FLAG); slot_ctx = xhci_get_slot_ctx(xhci, config_cmd->in_ctx); slot_ctx->dev_info |= cpu_to_le32(DEV_HUB); + /* + * refer to section 6.2.2: MTT should be 0 for full speed hub, + * but it may be already set to 1 when setup an xHCI virtual + * device, so clear it anyway. + */ if (tt->multi) slot_ctx->dev_info |= cpu_to_le32(DEV_MTT); + else if (hdev->speed == USB_SPEED_FULL) + slot_ctx->dev_info &= cpu_to_le32(~DEV_MTT); + if (xhci->hci_version > 0x95) { xhci_dbg(xhci, "xHCI version %x needs hub " "TT think time and number of ports\n", |